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We propose a method to remedy finite sample coverage problems and improve upon the efficiency of commonly employed procedures for the construction of nonparametric confidence intervals in regression kink designs. The proposed interval is…

Econometrics · Economics 2021-11-23 Majed Dodin

This paper studies robust nonparametric regression, in which an adversarial attacker can modify the values of up to $q$ samples from a training dataset of size $N$. Our initial solution is an M-estimator based on Huber loss minimization.…

Statistics Theory · Mathematics 2023-12-12 Puning Zhao , Zhiguo Wan

The idea of best approximation in linear n-normed space is presented and some examples showing various possibilities of best approximations in linear n-normed space is given. Also, we study strictly convex n-norm and enquire about the…

Functional Analysis · Mathematics 2023-09-27 Prasenjit Ghosh , T. K. Samanta

In 1958, Sz\"{u}sz proved an inhomogeneous version of Khintchine's theorem on Diophantine approximation. Sz\"{u}sz's theorem states that for any non-increasing approximation function $\psi:\mathbb{N}\to (0,1/2)$ with $\sum_q \psi(q)=\infty$…

Number Theory · Mathematics 2021-06-15 Han Yu

This work is dedicated to the study of both large-$N$ and perturbative quantum behaviors of Lifshitz nonlinear sigma models with dynamical critical exponent $z=2$ in 2+1 dimensions. We discuss renormalization and renormalization group…

High Energy Physics - Theory · Physics 2016-07-01 Pedro R. S. Gomes , M. Gomes

We consider an interacting Lifshitz field with z=3 in a curved spacetime. We analyze the renormalizability of the theory for interactions of the form lambda phi^n, with arbitrary even n. We compute the running of the coupling constants both…

High Energy Physics - Theory · Physics 2012-02-03 Diana L. López Nacir , Francisco D. Mazzitelli , Leonardo G. Trombetta

Certain previously known upper bounds on the moments of the norm of martingales in 2-smooth Banach spaces are improved. Some of these improvements hold even for sums of independent real-valued random variables. Applications to concentration…

Probability · Mathematics 2017-01-17 Iosif Pinelis

Let $X$ be a Banach space. We prove that, for a large class of Banach or quasi-Banach spaces $E$ of $X$-valued sequences, the sets $E-\bigcup _{q\in\Gamma}\ell_{q}(X)$, where $\Gamma$ is any subset of $(0,\infty]$, and $E-c_{0}(X)$ contain…

Functional Analysis · Mathematics 2012-08-30 G. Botelho , D. Diniz , V. V. Favaro , D. Pellegrino

We obtain sharp approximation results for into nearisometries between Lp spaces and nearisometries into a Hilbert space. Our main theorem is the optimal approximation result for nearsurjective nearisometries between general Banach spaces.

Functional Analysis · Mathematics 2007-05-23 Peter Semrl , Jussi Vaisala

The purpose of this article is twofold: first of all, we want to define two norms using the space of intrinsically Lipschitz sections. On the other hand, we want to generalize an Extension Theorem proved by the author in the context of the…

Metric Geometry · Mathematics 2023-01-05 Daniela Di Donato

A regularization algorithm allowing random noise in derivatives and inexact function values is proposed for computing approximate local critical points of any order for smooth unconstrained optimization problems. For an objective function…

Optimization and Control · Mathematics 2021-04-07 S. Bellavia , G. Gurioli , B. Morini , Ph. L. Toint

Proximal gradient methods are a popular tool for the solution of structured, nonsmooth minimization problems. In this work, we investigate an extension of the former to general Banach spaces and provide worst-case convergence rates for,…

Optimization and Control · Mathematics 2025-09-30 Gerd Wachsmuth , Daniel Walter

Let $X_N$ be an $N$-dimensional subspace of $L_2$ functions on a probability space $(\Omega, \mu)$ spanned by a uniformly bounded Riesz basis $\Phi_N$. Given an integer $1\leq v\leq N$ and an exponent $1\leq q\leq 2$, we obtain universal…

Functional Analysis · Mathematics 2021-07-27 Feng Dai , V. Temlyakov

We develop tools to produce equivalent norms with specific local geometry around infinitely many points in the sphere of a Banach space via an inductive procedure. We combine this process with smoothness results and techniques to solve two…

Functional Analysis · Mathematics 2022-11-23 Andrés Quilis

We use the theory of rectifiable metric spaces to define a Dirichlet energy of Lipschitz functions defined on the support of integral currents. This energy is obtained by integration of the square of the norm of the tangential derivative,…

Differential Geometry · Mathematics 2014-11-07 Jacobus W. Portegies

For a metric space $X$, we study the space $D^{\infty}(X)$ of bounded functions on $X$ whose infinitesimal Lipschitz constant is uniformly bounded. $D^{\infty}(X)$ is compared with the space $\LIP^{\infty}(X)$ of bounded Lipschitz functions…

Metric Geometry · Mathematics 2009-01-22 E. Durand , J. A. Jaramillo

We extend our investigation of the IR effects on the local dynamics of matter fields in quantum gravity. Specifically we clarify how the IR effects depend on the change of the quantization scheme: different parametrization of the metric and…

High Energy Physics - Theory · Physics 2013-05-17 Hiroyuki Kitamoto , Yoshihisa Kitazawa

We introduce some new functions spaces to investigate some problems at or beyond endpoint. First, we prove that Bochner-Riesz means $B_R^\lambda$ are bounded from some subspaces of $L^p_{|x|^\alpha}$ to $L^p_{|x|^\alpha}$ for $…

Classical Analysis and ODEs · Mathematics 2011-03-04 Shunchao Long

Using techniques developed recently in the field of compressed sensing we prove new upper bounds for general (nonlinear) sampling numbers of (quasi-)Banach smoothness spaces in $L^2$. In particular, we show that in relevant cases such as…

Numerical Analysis · Mathematics 2023-08-02 Thomas Jahn , Tino Ullrich , Felix Voigtlaender

We consider the problem of approximating an unknown function from point evaluations. This problem is a crucial subproblem in many modern (nonlinear) approximation schemes. When obtaining these point evaluations is costly, minimising the…

Numerical Analysis · Mathematics 2025-12-03 Philipp Trunschke , Anthony Nouy